Functional Programming in Perl

Syntactic Difficulties

But now you end up with horrors like this:

        val statement =
          alternate(concat(concat(concat(identifier, token "="),
                                  expression), token ";"),
                    concat(concat(token "PRINT", expression),
                           token ";"),
                    token ";");

So Paulson uses ML's operator overloading to add some syntactic sugar:

        val statement =
             identifier - token("=") - expression - token(";")
           | token("PRINT") - expression          - token(";")
           |                                        token(";");

This makes the difference between a usable and an unusable system